I just got a used j3 for $240 including 2 year warranty.
Everything seems good but one thing so far...

I formatted the j3 btw
The screen turns black and locks if I leave it untouched for a couple minutes..
Then when I pick it up to navigate, i forget its lock then I would have to consistantly click the power/lock button on the side..
THIS IS GETTING VERY ANNOYING!